HL 60 cells are being treated with agents that induce differentiation towards either granulocyte or monocytic populations. The uninduced and induced population are fractionated using a one gravity cell separator (LACS) into subpopulations of narrow maturity ranges. The more mature the cells, the more their nuclease patterns resemble those of normal mature granulocytes. Mouse peritoneal macrophages from a variety of mouse strains are being elicited by a variety of agents and activated by BCG. Upon treatment, nuclease activity is greatly augmented, and there is a change in enzyme content indicative of low molecular weight charge modifications. These changes parallel the elicited and activated statue of these cells as measured by traditional methods. Currently, this study is being extended to other rodent groups to determine the universitality of our findings and to allow the investigation of macrophages from other body sites.